Volume 4, Issue 1, Pages 124-134 (July 2013) Prion-like Properties of Pathological TDP-43 Aggregates from Diseased Brains  Takashi Nonaka, Masami Masuda-Suzukake, Tetsuaki Arai, Yoko Hasegawa, Hiroyasu Akatsu, Tomokazu Obi, Mari Yoshida, Shigeo Murayama, David M.A. Mann, Haruhiko Akiyama, Masato Hasegawa  Cell Reports  Volume 4, Issue 1, Pages 124-134 (July 2013) DOI: 10.1016/j.celrep.2013.06.007 Copyright © 2013 The Authors Terms and Conditions

Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure 1 Detergent-Insoluble Fractions from ALS and FTLD-TDP Brains Function as Seeds for Intracellular Aggregation of Plasmid-Derived TDP-43 (A) Immuno-electron microscopy analyses of insoluble fractions from diseased brains (types A, B, and C). Filamentous structures are labeled with anti-phospho TDP-43 antibody (pS409/410). Scale bars represent 200 nm in upper panel, 50 nm in lower panel. (B) Immunoblot analysis of lysates from cells expressing HA-TDP-43 plasmid only (HA-TDP-43), cells treated with ALS ppt (5 μg; ALS ppt), cells transfected with both HA-TDP-43 and ALS ppt (HA-TDP-43 + ALS ppt), and cells transfected with both HA-TDP-43 and FTLD ppt (5 μg; HA-TDP-43 + FTLD ppt). Proteins were differentially extracted from cells with Tris-HCl (TS), Triton X-100 (TX), and sarkosyl (Sar), leaving the pellet (ppt). Blots were probed using anti-HA (upper) and anti-pS409/410 (lower). In the right panel, the Sar-ppt fractions are shown side by side. 1: HA-TDP-43; 2: ALS ppt; 3: HA-TDP-43 + ALS ppt; 4: HA-TDP-43 + FTLD ppt. The immunoreactivity of each lane that was positive for anti-pS409/410 was quantified and the results are expressed as means + SEM (n = 3). ∗∗p < 0.0005 by Student’s t test; a.u., arbitrary unit. See also Figure S1. (C) Immunoblot analysis of proteins extracted from cells expressing only nontagged TDP-43 plasmid (TDP-43), cells treated only with ALS ppt (ALS ppt), and cells transfected with both TDP-43 and ALS ppt (TDP-43 + ALS ppt). Blots were probed using anti-TDP-43 monoclonal antibody (upper) and anti-pS409/410 (lower). No bands were detected when only ALS ppt (5 μg) used as seeds was loaded on the gel (rightmost lane). (D) ID of ALS ppt was performed with (+) or without (−) a mixture of anti-TDP-43 and anti-pS409/410 antibody. This was followed by immunoblot analyses with anti-pS409/410 (left panel). Proteins differentially extracted from cells expressing only HA-TDP-43 plasmid (HA-TDP-43), and cells transfected with both HA-TDP-43 and immunodepleted ALS ppt (HA-TDP-43 + ALS ppt ID) or untreated ALS ppt (HA-TDP-43 + ALS ppt) were analyzed. Blots were probed using anti-HA (upper) and anti-pS409/410 (lower). (E) Confocal laser microscopy analyses of cells expressing only HA-TDP-43 plasmid (HA-TDP-43), cells treated with detergent-insoluble fraction of ALS brain (ALS ppt), and cells transfected with both HA-TDP-43 and ALS ppt (HA-TDP-43 + ALS ppt) immunostained with anti-HA (red), anti-pS409/410 (green) or anti-Ub (green), and counterstained with TO-PRO-3 (blue). Scale bars represent 10 μm. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure 2 Time Course of Production of TDP-43 CTFs (A and B) Cells transiently expressing HA-TDP-43 plasmid treated without (A) or with (B) ALS ppt were incubated for 1–3 days and then harvested. Proteins were differentially extracted and subjected to immunoblot analyses. Blots were probed with anti-pS409/410. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure 3 Formation of Self-Templating Aggregates Induced by Insoluble TDP-43 from the Brains of Patients (A) Immunoblot analyses of Sar-ppt prepared from several diseased brains used as seeds. (B) Immunoblot analyses of Sar-ppt of cells expressing TDP-43 treated with each seed (Nos. 1–10). (C) Comparison of band patterns of Sar-ppt fractions from cells expressing full-length TDP-43 (FL) or TDP-43 lacking nuclear localization signal (78–84 residues: ΔNLS) treated with type A, B, or C seed. Sar-ppt fractions from each of the diseased brains are shown next to cellular ppt fractions on the same blot. A schematic diagram of the band pattern of TDP-43 CTFs is also presented. Blots were probed using anti-pS409/410. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure 4 Characterization of the Prion-like Properties of Detergent-Insoluble TDP-43 from Brains (A) Immunoblot analyses of cells expressing HA-TDP-43 and treated with Triton X-100-insoluble fractions (TX-insoluble seeds) prepared from the following cells, using anti-HA (upper) and anti-pS409/410 (lower): none, mock cells; HA-TDP-43, cells expressing HA-TDP-43; and HA-TDP-43+ALS ppt, cells expressing HA-TDP-43 and treated with ALS ppt. These TX-insoluble seeds (10 μg each) were also immunoblotted with anti-pS409/410 (lower right). (B) Confocal laser microscopy analyses of cells expressing HA-TDP-43 and treated with TX-insoluble seed from cells transfected with both HA-TDP-43 and ALS ppt (HA-TDP-43+ALS ppt) immunostained with anti-HA (red), anti-pS409/410 (green), or anti-Ub (green), and counterstained with TO-PRO-3 (blue). Scale bars: 10 μm. (C) Effect of heat treatment on the seeding ability of each type of seed. Each seed before and after heat treatment (100°C for 5 min) was analyzed by immunoblotting using anti-pS409/410 (left). Then, cells expressing TDP-43 were treated with these fractions as seeds. After 3 days of incubation, Sar-ppt fractions were prepared and analyzed by immunoblotting using anti-pS409/410 (middle). The immunoreactivity of each lane that was positive for anti-pS409/410 was quantified and the results are expressed as means + SEM (n = 3). ∗∗p < 0.0001 by Student’s t test; n.s., not significant; a.u., arbitrary unit. See also Figure S3. (D) Effect of ProK on the seeding ability of each type of seed. Each seed before and after ProK digestion (final 20 μg/mL ProK at 37°C for 30 min) was analyzed by immunoblotting using anti-pS409/410 (left). Then, cells expressing TDP-43 were treated with these fractions as seeds. After 3 days of incubation, the Sar-ppt fractions were analyzed by immunoblotting using anti-pS409/410 (middle). The immunoreactivity of each lane that was positive for anti-pS409/410 was quantified and the results are expressed as means + SEM (n = 3). n.s., not significant; a.u., arbitrary unit. See also Figure S3. (E) Effect of formic acid (FA) on the seeding ability of type A seed. Type A seed with or without FA treatment was analyzed by immunoblotting using anti-pS409/410 (left). Then, cells expressing TDP-43 were treated with these fractions as seeds. After 3 days of incubation, fractionated samples were analyzed by immunoblotting using anti-pS409/410 (right). The immunoreactivity of ppt fractions that were positive for anti-pS409/410 was quantified and the results are expressed as means + SEM (n = 3). ∗∗p < 0.0001 by Student’s t test. a.u., arbitrary unit. See also Figure S3. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure 5 Cell Death Induced by the Formation of Intracellular TDP-43 Aggregates (A) The extent of cell death of transfected cells was quantified by an LDH release assay. Cells treated with type B seed alone (type B), cells transfected with TDP-43 plasmid alone, or cells expressing TDP-43 and treated with Sar-ppt from type A, B, or C, or Pick’s disease brains were cultured, and a cell death assay was performed 3 days thereafter. The results are expressed as means + SEM (n = 5). ∗p < 0.05 versus “none” by Student’s t test. (B) Immunoblot analyses of Sar-ppt from cells expressing TDP-43 and treated with extracts of type A, B, C, and Pick’s disease brains, using anti-pS409/410. Immunoreactivity to anti-pS409/410 was quantified in each lane. The results are expressed as means + SEM (n = 3). ∗∗p < 0.001 versus “none” by Student’s t test. a.u., arbitrary unit. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure 6 Proteasome Dysfunction in Cells Bearing Intracellular TDP-43 Aggregates (A–C) SH-SY5Y cells transfected with both GFP-CL1 and TDP-43 were treated with ALS ppt for 2 days. (A) As a control, cells expressing GFP-CL1 with or without 0.1 μM MG132 or ALS ppt, and cells expressing both GFP-CL1 and TDP-43 were also analyzed. (B) The intensity of GFP fluorescence in these cells was quantified. The results are expressed as means + SEM (n = 3). ∗p < 0.05; ∗∗p < 0.001 versus the value of GFP-CL1 by Student’s t test. a.u., arbitrary unit. (C) Cells transfected with both GFP-CL1 and TDP-43 and treated with ALS ppt were stained with anti-pS409/410. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure 7 Intracellular TDP-43 Aggregates Are Released in Association with Exosome (A) Coculture of cells expressing DsRed and cells having intracellular TDP-43 aggregates in a 1:1 ratio. After incubation for 3 days, cells were stained with pS409/410 (green) and counterstained with TO-PRO-3 (blue). The graphs show the intensity distribution profile of DsRed (red line), phosphorylated TDP-43 (green line), and TO-PRO-3, a nuclear marker (blue line), in the merged image. Scale bars: 10 μm. (B) Cross-sections of reconstructed TDP-43 aggregates in these cocultured cells. (a) One of the optical sections (X-Y) at the depth indicated with blue lines in (b) and (c). (b) Cross-sectional Y-Z image along the green line indicated in (a). (c) Cross-sectional X-Z image along the red line indicated in (a). Red, DsRed; green, phosphorylated TDP-43 aggregate positive for anti-pS409/410; blue, TO-PRO-3 (nuclei). Scale bars: 10 μm. (C) Immunoblot analyses of exosome fractions prepared from culture medium of cells expressing TDP-43 (TDP-43), cells treated with ALS ppt alone (ALS ppt), and cells expressing TDP-43 and treated with ALS ppt (TDP-43+ALS ppt). Blots were probed with anti-TDP-43 monoclonal (ProteinTech) and an antibody against CD63 (SBI). Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure S1 Intracellular Aggregation of TDP-43 in 293T Cells and Dose-Dependent Effects of Seeds from Diseased Brain on Intracellular TDP-43 Aggregate Formation, Related to Figure 1 (A) Immunoblot analysis of proteins differentially extracted from 293T cells expressing only HA-TDP-43 plasmid (HA-TDP-43) and cells transfected with both HA-TDP-43 and ALS ppt (HA-TDP-43 + ALS ppt). (B) Immunoblot analyses of cells expressing HA-TDP-43 and treated with detergent-insoluble fraction prepared from FTLD-TDP brains (FTLD ppt). Different amounts of FTLD ppt were introduced into cells with Multifectam. Immunoblot analyses were performed with anti-HA and pS409/410 antibodies. Immunoreactive bands at 50 kDa in TX-insoluble fractions positive for anti-pS409/410 were quantified. The results are expressed as means + SEM (n = 3). Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure S2 Insoluble TDP-43 and α-Synuclein Fibril Do Not Serve as Seeds for the Aggregation of α-Synuclein and TDP-43, Respectively, Related to Results (A and B) Immunoblot analysis of lysates from cells expressing α-synuclein plasmid only (aS), cells expressing aS treated with recombinant aS fibrils (aS + aS fibrils), cells treated with detergent-insoluble fraction of ALS brain (ALS ppt), and cells transfected with both aS and ALS ppt (aS + ALS ppt). Blots were probed using anti-phosphorylated aS (PSer129) antibody. (C) Immunoblot analysis of lysates from cells expressing aS or HA-TDP-43 treated with or without aS fibrils. Blots were probed using anti-PSer129 or anti-pS409/410. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions

Figure S3 Characterization of Detergent-Insoluble TDP-43 Prepared from Cells Containing TDP-43 Aggregates and Effects of Heat, Proteinase K, or Formic Acid Treatment of Insoluble TDP-43 on Seeding Ability, Related to Figure 4 (A) Immunoblot analysis of Sar-ppt fractions prepared from cells treated with or without insoluble fraction of cells expressing HA-TDP-43 treated with ALS ppt. Blots were probed using anti-pS409/410. Note that insoluble fraction of cells expressing HA-TDP-43 treated with ALS ppt does not serve efficiently as seeds in normal cells. (B) Immunoblot analysis of proteins differentially extracted from SH-SY5Y cells expressing TDP-43 plasmid transduced with type A, B or C seeds after heat treatment (100°C for 5 min). Blots were probed using anti-pS409/410 antibody. Note that type A seed retains the ability to seed for aggregation after the heat treatment (i.e., it shows high stability). (C) Immunoblot analysis of proteins differentially extracted from SH-SY5Y cells expressing TDP-43 plasmid transduced with type A, B or C seeds after proteinase K (ProK) digestion. Blots were probed using anti-pS409/410 antibody. Note that seeding ability of all types of seeds is retained after the ProK treatment. (D and E) Cells expressing TDP-43 were treated with type B or C seeds with or without formic acid (FA) treatment. After 3-days incubation, cells were harvested and fractionated samples were analyzed by immunoblotting using anti-pS409/410. Note that the seeding activity of type B (A) and C (B) seeds are almost lost after FA treatment. Cell Reports 2013 4, 124-134DOI: (10.1016/j.celrep.2013.06.007) Copyright © 2013 The Authors Terms and Conditions